<div dir="ltr"><div>I am not fully familiar with Flash but very often this kind of problem comes from your equation of state....try to check it.</div><div>Hoping that helps you</div><div>Michel<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 17 avr. 2019 à 19:00, <<a href="mailto:flash-users-request@flash.uchicago.edu">flash-users-request@flash.uchicago.edu</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Send flash-users mailing list submissions to<br>
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Today's Topics:<br>
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1. The problem of Negative Internal Energy in 3T MHD simulation<br>
with laser generated plasmas (Huo Wenyi)<br>
<br>
<br>
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Message: 1<br>
Date: Wed, 17 Apr 2019 07:43:27 +0000<br>
From: Huo Wenyi <<a href="mailto:Wenyi.Huo@eli-beams.eu" target="_blank">Wenyi.Huo@eli-beams.eu</a>><br>
Subject: [FLASH-USERS] The problem of Negative Internal Energy in 3T<br>
MHD simulation with laser generated plasmas<br>
To: "<a href="mailto:flash-users@flash.uchicago.edu" target="_blank">flash-users@flash.uchicago.edu</a>" <<a href="mailto:flash-users@flash.uchicago.edu" target="_blank">flash-users@flash.uchicago.edu</a>><br>
Message-ID: <<a href="mailto:4b8b49f0356446ab9b4326bb39c14550@eli-beams.eu" target="_blank">4b8b49f0356446ab9b4326bb39c14550@eli-beams.eu</a>><br>
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<br>
Dear all:<br>
<br>
I am using FLASH to simulate the magnetohydrodynamics in laser generated plasmas. However, I always encounter a problem of negative internal energy both in FLASH 4.5 and FLASH4.6. Does anyone encounter such a similar problem? The error information in the Log file is as follows:<br>
<br>
<br>
[ 04-16-2019 14:34:35.488 ] [hy_uhd_ragelike] ERROR DETECTED<br>
[ 04-16-2019 14:34:35.488 ] Zero or negative advected specific internal energy detected<br>
[ 04-16-2019 14:34:35.488 ] DENS_OLD = 1.0000904290291E-09<br>
[ 04-16-2019 14:34:35.488 ] DENS_NEW = 1.0000983091349E-09<br>
[ 04-16-2019 14:34:35.488 ] UTOT_NEW = -3.7386802822434E-01<br>
[ 04-16-2019 14:34:35.488 ] UEXTRA = -1.7491864582091E+01<br>
[ 04-16-2019 14:34:35.488 ] UELE_NEW = -3.7135596091566E-01<br>
[ 04-16-2019 14:34:35.488 ] UION_NEW = -2.5120492887951E-03<br>
[ 04-16-2019 14:34:35.488 ] URAD_NEW = -1.8019885718467E-08<br>
[ 04-16-2019 14:34:35.488 ] EELE_VAR = 1.7001438966846E+10<br>
[ 04-16-2019 14:34:35.488 ] EION_VAR = 1.1498940630502E+08<br>
[ 04-16-2019 14:34:35.488 ] ERAD_VAR = 8.2498749422145E+02<br>
[ 04-16-2019 14:34:35.488 ] EELE = -3.7131945682109E+08<br>
[ 04-16-2019 14:34:35.488 ] EION = -2.5118023556785E+06<br>
[ 04-16-2019 14:34:35.488 ] ERAD = -1.8018114373230E+01<br>
[ 04-16-2019 14:34:35.488 ] uele_adv = 1.7002978536045E+01<br>
[ 04-16-2019 14:34:35.488 ] uion_adv = 1.1501719275908E-01<br>
[ 04-16-2019 14:34:35.488 ] urad_adv = 8.2506210304961E-07<br>
[ 04-16-2019 14:34:35.488 ] PELE_VAR = 1.2145270532940E+00<br>
[ 04-16-2019 14:34:35.488 ] PION_VAR = 7.6660475248193E-02<br>
[ 04-16-2019 14:34:35.488 ] PRAD_VAR = 2.7502069901319E-07<br>
[ 04-16-2019 14:34:35.488 ] PELE_ADV = 1.2145343502140E+00<br>
[ 04-16-2019 14:34:35.488 ] PION_ADV = 7.6672066071296E-02<br>
[ 04-16-2019 14:34:35.488 ] PRAD_ADV = 2.7502070101654E-07<br>
[ 04-16-2019 14:34:35.488 ] TELE_VAR = 6.0996867323016E+02<br>
[ 04-16-2019 14:34:35.488 ] TION_VAR = 3.6907447766733E+00<br>
[ 04-16-2019 14:34:35.489 ] TRAD_VAR = 1.0219015193890E+02<br>
[ 04-16-2019 14:34:35.489 ] CELL X = 3.3222656250000E-01<br>
[ 04-16-2019 14:34:35.489 ] CELL Y = 6.9890625000000E-01<br>
[ 04-16-2019 14:34:35.489 ] CELL Z = 0.0000000000000E+00<br>
[ 04-16-2019 14:34:35.489 ] You might be able to get things to keep running by trying<br>
[ 04-16-2019 14:34:35.489 ] more diffusive hydro options (reduce CFL, order, etc...)<br>
[ 04-16-2019 22:00:17.496 ] [hy_uhd_ragelike] Negative internal energies in 3T update<br>
[ 04-16-2019 22:00:17.496 ] Falling back to using internal energy ratios instead of pressure ratios<br>
<br>
<br>
<br>
<br>
I have tried many different RiemannSolvers. It does not help. I guess that this problem is related to the grid size, but I am not sure.<br>
<br>
Can anyone provide a solution to this problem? Thank you very much!<br>
<br>
Best regards,<br>
<br>
Wenyi Huo<br>
<br>
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